/// 将字符串转换成数字
/// @param {String} $string
/// @author Hugo Giraudel
/// @link http://hugogiraudel.com/2014/01/15/sass-string-to-number/

@function number($string) {
  // Matrices
  $strings: '0' '1' '2' '3' '4' '5' '6' '7' '8' '9';
  $numbers: 0 1 2 3 4 5 6 7 8 9;

  // Result
  $result: 0;
  $divider: 0;
  $minus: false;

  // Looping through all characters
  @for $i from 1 through str-length($string) {
    $character: str-slice($string, $i, $i);
    $index: index($strings, $character);

    @if $character == '-' {
      $minus: true;
    } @else if $character == '.' {
      $divider: 1;
    } @else {
      @if not $index {
        $result: if($minus, $result * -1, $result);
        @return unit-length($result, str-slice($string, $i));
      }

      $number: nth($numbers, $index);

      @if $divider == 0 {
        $result: $result * 10;
      } @else {
        // Move the decimal dot to the left
        $divider: $divider * 10;
        $number: $number / $divider;
      }

      $result: $result + $number;
    }
  }

  @return if($minus, $result * -1, $result);
}
